1. Field of Invention
The present invention relates to a foldable, multisectional airfoil with apparatus enabling it to fold or curl up or down about the body of a craft; and to a system to maintain airfoil rigidity during flight.
2. Description of Prior Art
The advantages of folding aircraft wings, have, in the past, been described largely in terms of ease in storage and transportation. As we approach an age in which--with radically stronger and lighter materials--giant strides will be made in aircraft innovation, the concept of readily foldable airfoil moves from the desirable to the essential.
Since the dawn of flight, myriad systems have been suggested to enable man's "wings", like birds wings, to not only bear weight during flight, but also to fold readily upon landing. Many folding wing designs are disclosed in the art, including semi-rigid airfoils, completely detachable wings, and wings systems that rotate and/or pivot. Yet, despite the multiplicity of designs, none has proved satisfactory for general use in terms of weight, cost, compactness, design simplicity and reliability. The core problem with detachable wings is the very fact that they must be detached, a process that requires time, tools, manpower and exposure to the elements. These disadvantages are equally present in all extant folding wing systems, since expense or complexity of design has almost entirely precluded automation.
Semi-rigid airfoil are more easily automated (see U.S. Pat. No. 3,599,904, filed Jun. 28, 1968) and may not share the disadvantages listed above; however, their use is also limited, as they are not strong enough to serve in heavy or high speed craft.
Rigid wings, on the other hand, possess strength but lack the flexibility of the semi-rigid structure. The rotating and pivoting systems in the art (in which right and left side wing segments move in one piece up or back) represent attempts to add flexibility but they have their own problems: rotating systems decrease the aerodynamics of the vehicle on the ground and pivoting systems can obstruct or limit cargo and passenger space.
In fact, these types of folding systems gain only a little flexibility and may pay a price in diminished safety. In order to gain real flexibility, a rigid airfoil would have to be multisegmented, but thus far additional segmentation has compromised airfoil strength in direct relation to the flexibility gained. Therefore, few multisegmented rigid airfoils are found in the art.
The present invention fulfills the aforementioned objects and overcomes limitations and disadvantages of prior art solutions to existing problems by providing a multisegmented, rigid wing which may be folded or "curled" about the body of an aircraft to permit aerodynamic contours.